Determination and monitoring of the microbial load on a variety of surfaces is often highly desirable. In the environmental field, for example, collection of surface and air samples for microbiological analysis poses a significant challenge. Likewise, food surfaces in the food industry, such as food contact surfaces, and non-food contact surfaces all represent points of microbial harborage or opportunities for cross-contamination. An example of a typical food surface is an animal carcass surface. At present, carcass surfaces are most commonly sampled either using moistened sponges, or by excising a thin portion of the surface using a knife. While both of these prior art devices and methods have numerous laudable benefits, they have a multiple shortcomings that detract from utility.
Sponge sampling, for example, requires execution of a prolonged series of procedural steps to ensure that the sampling media: is aseptically extracted from its packaging prior to use; is applied to the surface in a way that collects microbial contamination in a representative manner; and is returned to the packaging in such a way as to prevent cross-contamination and loss of sample integrity. Variations in technique, such as pressure during application, number of ‘passes,’ and/or whether or not an ‘area template’ is used, can result in an undesirable level of variable results.
Likewise, excision sampling requires execution of a prolonged series of procedural steps to ensure that the instruments used to excise the sample are sterile, and that a portion of the sample is excised in a way that collects microbial contamination in a representative manner, and that the sample is packaged in such a way as to prevent cross-contamination and loss of sample integrity. Moreover, removal of a portion of the surface by excision can be detrimental to the aesthetic quality and desirability of the food product. Furthermore, variations in the depth and technique of the excision can lead to a greater or lesser mass of food product being included in the sample, thereby making it difficult to interpret and normalize the data in terms of microbial contamination per unit surface area.
Additionally, it is often desirable to form a composite sample for the purposes of determining an average value for a microbial determinant of interest. In this instance, because methods such as sponge and excision sampling collect unit samples, additional effort must be expended to combine multiple samples to form one composite sample. Such additional effort can require significant time, and increase the probability that procedural errors (e.g., cross-contamination and/or miscounting) will be introduced.
Therefore, there is a pronounced need in the art for less labor intensive methods of microbial sampling of surfaces including, but not limited to food surfaces, food contact surfaces, and non-food contact surfaces.
There is a pronounced need in the art for more accurate methods of microbial sampling of surfaces which reduce variations in the manner in which samples are collected, thereby reducing overall errors in the results.
There is a pronounced need in the art for methods of microbial sampling of surfaces that facilitate the collection of composite samples, shortening the time required, and reducing the errors otherwise associated with the formation of the composite sample.
There is a pronounced need in the art for non-invasive methods of microbial sampling of food surfaces which are less detrimental to the aesthetic quality and desirability of the food product.